Hide and leather working machine



Feb. 26, 1952 R. J. STEHLENG 2,586,879

HIDE AND LEATHER WORKING MACHINE Filed May 29, 1950 5 Sheets-Sheet lFeb. 26, 1952 R. J. STEHLING 2,586,879

HIDE AND LEATHER WORKING MACHINE Filed May 29, 1950' 3 Shets-Shet 2 Feb.26, 1952 R. J. STEHLING HIDE AND LEATHER WORKING MACHINE Sheefcs-Sheet 3Filed May 29, 1950 JfdZph 151mm;

Patented Feb. 2 6, 1952 HIDE AND LEATHER WORKING MACHINE Ralph J.Stehling, Milwaukee, Wis., assignor to Chas. H. Stehling Company,Milwaukee, Wis., a corporation of Wisconsin Application May 29, 1950,Serial No. 164,945

10 Claims.

This invention relates to hide and leather working machines such asfieshing machines and wrmgers in which the lower one of a pair ofsuperimposed pressure rollsis swungbetween a loading position and anoperative position, directly under the upper roll. When the lower rollis swung to its loading position the machine is said to be open allowinga wet hide or skin to be draped over the lower roll, and as the lowerroll is swung to its operative position to close the machine the hide orskin draped thereover 1s gripped and squeezed between it and the upperroll which is yieldingly pressed downward.

Heretofore the means for pressing the upper roll downward consisted ofheavy coi1 springs confined between the bearings in which the upper rollis journalled and adjustable pressure nuts. This construction isillustrated in Patent No. 2,094,761, issued to J. J. Stehling, October5, 1937.

lhe mechanism by which the lower roll is swung to and from its operativeposition origi nally was mechanically driven as in the aforesaid patent.Subsequently hydraulic means were substituted for the mechanical drivemechanism as shown in Patent No. 2,471,984, issued to R. J.

Stehling, May 31, 1949. While the substitution of the hydraulic means ofthe latter patent for the mechanical drive employed in the former was adefinite improvement, the retention of the heavy compression springs toprovide the yielding pressure upon the work still left the machine witha serious fault.

It is, of course, desirable that uniform pressure be exerted upon allportions of the hide or skin passing through the machine, but since 9.hide or skin seldom has the same thickness throughout its entire area itfollows that as it passes between the rolls the upper roll rides up anddown with increasing and decreasing thicknesses. Where the pressure isderived from springs such up and down movement of the upper rollcorrespondingly increasediand decreased the compression and consequentlythe force exerted by the springs. Also the springs were difficult andtedious to adjust.

The purpose and object of this invention is therefore, to eliminate thepressure springs which characterized machines of this type heretofore inuse and to substitute hydraulic means for applying the pressure upon theupper roll so that regardless of variation .in the thickness of theskins or hides the same pressure will .be exerted upon .allportionsthereof.

Another object .of this invention is toprovide a simple control for thehydraulic pressure applying means which functions to automatically causethe rolls to be forced together as .the machine is closed and to relievesuch pressure asthe machine is opened.

Another object of this invention is to provide hydraulic means forsuspending the upper roll during the time the machine is open anddirectly upon closure to press .the rolls together .so that the upperroll in nowise resists or op oses closure of the machine.

As in the aforesaid patent .to RhJ. ,Stehling No. 2,471,984, the fluidpressure for operating the opening .and closing mechanism isderived-irom a variable volume constant pressure pump, and since themounting ,for the lower roll and the means for swinging .it to and fromoperative position are so designed that retention of the lower roll inits operative position imposes no load upon the pump, the .full outputof the pump is available to provide the pressure upon the upper roll.Accordingly, this invention utilizes the same variable volumeconstantpressure pump which provides the fluid pressureneeded to swing the lowerroll to and from its operative position to also energize the hydraulicmeans for supplying the downward pressure upon the upper ,roll. In .thismanner both functions are performed without increasing the powerrequirements of the machine. More important, however, is the fact thatadjustment of the pressure applied upon the work is greatly simplified.and improved .as will appear hereinafter.

With theabove and other objects in View, which will appear as thedescription proceeds, this invention resides in the novel construction,combination and arrangement of parts substantially as hereinafterdescribed and more particularly defined by the appended claims, .itbeing understood that .such changes in the precise embodiment .of thehereindisclosed invention may be made as come within the scope of theclaims.

The accompanying drawings illustrate. two complete examples of thephysical embodiments ,of the invention constructed according to the.best modes so far devised for the practical application of theprinciples thereof, and in which:

Figure l is ,a perspective view, more or less diagrammatic, illustratingthe main elements .of a leather wringing machine embodying thisv,invention, parts of said view being broken ,away "to better illustratedetails;

Figure 2 is a more or less diagrammatic .crqss sectional view throughthe machine showin the same open, that is, with its lower rplL wung out;

Figure 3is,a View similar to Figure2 ibutshowing the machine closed andthe lower roll .in 5 operative position coacting with the upper roll;

, erally by the numeral 22. incorporates the essentials of the hydraulicdrive Figure 4 is a fragmentary detail cross sectional view taken fromthe same direction as Figures 2 and 3 and illustrating particularly theautomatic control for the hydraulic pressure applying means by which theupper roll is forced downwardly against the lower roll as the machine isclosed; and

Figure 5 is a view similar to Figure 4 but illustrating an added featureof the invention, namely, the hydraulic lifting of the upper roll as themachine is opened.

Referring now more particularly to the accompanying drawings in whichlike numerals indicate like parts throughout the several views, thenumerals 5 and 6 designate left and right hand end frames, respectively.These frames are rigidly mounted in fixed relation to one another bystructure not shown for the sake of clarity. Extending lon itudinallyacross the space between the end frames are upper and lower pressurerolls 1 and 8, respectively.

Where the machine is designed to operate essentially as a wringer, thatis, to wring out and straighten wet hides and skins, the two companionrolls have sleeves 9 and [0, respectively, of felt or other bibulousmaterial loosely encircling the same. Hence, as the skins or hides arepassed between the pressure rolls these sleeves 9 and I soak up thewater squeezed therefrom. For the sake of clarity the sleeves areomitted in Figure 1.

Also disposed in the space between the end frames and 6 and extendinglongitudinally of the machine is a so-called putting-out r011 H and arubber covered pressure roll l2 which serves to press the hide or skinagainst the puttingout" roll and ena es its oppos tely pitched helicalribs to work the hide or skin simultaneously in opposite directions andthereby straighten the ,same.

The mounting for the lower pressure roll and also the rubber coveredroll l2 comprises a pair of left hand and right hand swinging arms I4and I5 pivoted as at l6 and I! to the lower portion of the end frames 5and 6, respectively. Attention is directed to the fact that the commonaxis of the two pivotal connections I6 and l! is vertically in line withthe center of a vertical slot-like opening la in the upper portion ofeach end frame and in which the bearings I!) for the upper roll areslidably mounted.

Though the manner in which the putting out roll II and the rubbercovered pressure roll l2 are mounted forms no part of this invention, itmay be noted that the former is journalled in fixed. bearings 20 andthat the latter is journalled in spring pressed bearings 2| carried bythe swingingly mounted arms l4 and l 5, so that'as the machine is closedthese two rolls come together under spring compression.

Swinging movement is imparted to the arms M and I5 to close and open themachine by fluid pressure responsive mechanism indicated gen- Thismechanism 22 forming the subject matter of the aforesaid Patent No.2,471,984 and thus includes a rock shaft 23 journalled in bearings 24fixed to the end frames, a crank arm 25 secured to each end of the rockshaft and a connecting rod 26 connecting each crank arm with the upperfree end of one roll 1 or on dead center to close the machine,

while a half turn of the rock shaft in the opposite direction swings themovable roll 8 out from under the upper roll I to open the machine.

Rocking movement is imparted to the shaft 23 by a fluid pressure motorcomprising a piston 27 operating in a cylinder 28 and connected to arack 29 which meshes with a pinion 3,6 fixed to the rock shaft. The rack29 and pinion 35 are preferably encased within a housing 3! adapted tocontain lubricant, and the mechanism is so designed that full pressure,that is, the full area of the piston 21, is used during the closure ofthe machine. To a large degree, however, the necessity for this latteradvantage is obviated by the fact that with this invention the only workperformed by the hydraulic mechanism 22 durin closure of the machine isto swing the arms l6- l5 and lift the rolls 8 and i2 into operativeposition and in that embodiment of the invention shown in Figures 1 to4, inclusive, to lift the weight of the upper roll '5". With theconstruction shown in Figure 5, the load upon. the mechanism 22. is evenfurther reduced since in this case the upper roll is held up until themachine closes.

In both embodiments of the invention, however, as the machine is closedand the lower roll 8 assumes its operative position directly under theupper roll, fluid pressure responsive means, indicated generally by thenumeral 32, operates to exert a downward yielding force upon the upperroll 1. This fluid pressure responsive means comprises a piston 33connected to each bearing [9 and operating in a cylinder 34, fixed tothe top of the end frame. A conventional O-ring 35 seated in a groove inthe piston provides a leak proof connection between it and the bore ofthe cylind-er, and to accommodate any possible misalignment between thebearings and the pistons and the slight movement of the bearingsnecessitated by the nature of the work, the connections between thebearings and their respective pistons incorporates a limited amount ofplay. In that form of the invention shown in Figures 1 to 4, inclusive,this slight play is obtained by having the heads of the cap screws orbolts 36 employed to effect the connection between the piston andbearing spaced a slight distance from the top of the flange of thepiston connecting-rod through which they pass.

Projecting upwardly from the top of each piston 53 is a tension rod 3?with a nut 38 threaded upon its upper projecting end portion. Theengagement of this nut 38 with the top of the cylinder, as shown inFigure 2, limits the extent to which the upper roll may drop by gravityas the ma chine opens; and since in every case it is desirable thatduring closure of the machine the distance the upper roll is lifted (inthe embodiment shown in Figures 1 to 4, inclusive) be approximately thesame, and with heavy stock the upper roll during operation of thismachine is in a position farther from the lower roll than with lightstock, the operator adjusts the nuts 38 accordingly.

Fluid pressure is supplied to the mechanism 22 and the means 32 from asingle constant pressure variable volume pump 39 of known construction,which may be like that shown in Patent No. 2,064,421 issued December 15,1936. This pump embodies a suitable governor 4B which varies thedelivery in accordance with the pressure built up in the system andmaintains any constant pressure desired without" bypassing the oil orother liquid employed. One of the features of this type of pump is thefact thaat it may be readily regulated to maintain the maximum pressureat any desired" value. This regulating means comprises an adjustablescrew 4i for varying the tension of-a governor spring (not shown); thetension of whichdetermines' the pressure to be maintained.Tightening-the screw increases the maximum pressure and'viceversa; Thus,as will be clear the adj ustment' of'the pressure exerted upon the workis a very simple mattenc'omp'aredt with the'arduoustask of turning. thetension nuts of the previous constructions.

The high pressure or output side of. the pump 39 1s connected through aline with a manually controllable valve 43-which' preferably is of. thetreadle type having a foot treadle 44f anda. pawl and ratchet 45' bywhich the valve plug (not showny is rotated from one position toanotherwith successive depressions of the treadle. lines46 and t'l'lead fromthevalve 43;. the former connecting as at 48 with the cylinder 28. underthe" piston 211 and alsov with the-inlet portv of' a two-way valve 49.Upon depression ofthetreadle to close the machine: fluid pressure isestablished in the line 45' and" hence underthepiston 21 and at" thesame timezat' the inlet port'ofthe valve-49, which, however, is-springheld in a position atwhich: it providesa pressure. relief connectionbetween the cylinders $4" and the reservoir 50 of the pump. To this endthe valve 49'has one of" its discharge ports connected through abranched line 5! with the-top of each cylinder 34 and has another ofits-ports connected through a I line 52 with the reservoir 50.

Upon the connection of the cylinder 28 with the pressure side of thepump, the piston 2? is projected upwardly to rock the shaft 23 in aclockwise direction androt'at'e its crank arm 25 through 1'80 degrees,thereby swinging the arms l'4!5 to dispose themovable roll 3 on deadcenter directly under the nominally stationary roll 1. During thelast-few degrees o-f rotation-oithe rock shaft and as the machineisbeing closed; anarm 53 fixed to" the rock' shaft, as shown in dottedlines in Figure 4, collides with an actuating stem 54 projecting fromthe valve 49 to depress the same and thereby connecting the cylinders 34with the pressure side of the pump.

As fluid pressure is established in the cylinders 34 above the pistons33 the upper nominally stationary roll Tis pressed'd'own towardthe-movable roll to squeeze a hide or skin therebetween, and

it is important to note that" because the upper roll is pressed downhydraulically, all partsofthe hide or skin will be subjected to the samepressure regardless of variations in thickness.

It is also important to observe that at the time the movable roll 8 isswung into its operative position the cylinders 34 are'not' connectedwith the pressure side of the pump. Hence, the only resistance which theupper roll I can offer to the finalclosing of the machineis thatoccasioned by the weight of the upper roll and even this is eliminatedwith the modified embodiment'of the invention shown in Figure. 5. In thelatter case fluid pressure is at all times manifested in the cylinders34" either above the pistons 33' to press the upper roll downasdescribed or beneath the pistons 33" to lift the upper roll out of thepath of the movableroll as itassume's its operative position. Thisdesirable additional advantage is achieved by merely connecting anotherport of the valve 49 with the cylinders 34" beneath the pistons-33 bymeansof a line 55.

In its normal conditiorrthe' valve 49 communicates the lines 46 and 55and when the movable roll assumes its operative position and the arm 53depresses the actuatingplunger- 54;v the valve: 49 communicates thepressure line 46. withv the branched line 5| and communicates the line55 with. the returnv 1ine.52.. IlSTiS, of. course. understood:thatzinthis form of: the invention the bottom. of the cylinder 34'"isclosedi by. a wall 56 in which thepistonz. has a snug slidingfitpressure sealed by an. or-ring: 51. To: afford the necessary relative.motion between the: pistons 33' and the bearings whichv they suspend,the lower ends of thepiston rods haveball andsocket connections58;withlthebearings.

To open. the machine it is only necessary; to again;step uponthetreadle-44 which actuates the valve43rto connect. the-upper ends of thecylinders 285 with the fluid pressuresource through the linev 4! and.connect; the lower ends thereof through the; line 4.6 and. a return.line; 59, with the-reservoir 5.5!.

From. the foregoing description taken inconnection. with. the.accompanying drawings, itv will be; readily; apparentlto those skilled.inlth isl art that thisinventiongreatly. simplifies, the construction;and operationof machines of the character described. andthat theelimination of the me.- chanical parts which characterized machines ofthis typeheretofore in use is especially desirable in view of the messyconditions under which apparatus of this type must be-operated. Moreimportant, however, is'the fact that employment of fluid pressure toforce the upper roll down assures uniform pressurev upon all portions ofthe hide or skin moving, through the machine, notwithstanding variationsin thickness thereof, and the fact. that adjustment of the pressure tobe exerted entails merely tightening or loosening an adjusting screw onthe variable volume constant pressure pump which provides the fluidpressure source.

What I claim as my invention is:

1. In a machine having companion pressure rolls, one of which is movableto and from its operative position coacting with the other roll which isnominally stationary but has limited movement toward and from theoperative position. of the movable roll, the combination of fluidpressure responsive means for moving the movable roll to and from itsoperative position; fluid pressure responsive means for pressing thenominally stationary roll toward its companion; a variable volumeconstant pressure pump supplying fluid' under pressure to both said twofluid pressure responsive means; manually operable control means forgoverning the operation of the first named fluid pressure responsivemeans; and control means automatically rendering said second named fluidpressure responsive means operative as the movable roll assumes itsoperative position.

2'. In a hide and. leather working machine: a pair'of" companion rollsbetween which work to be acted upon passes, one of. said rolls beingnominally stationary and the other movable; means mounting the nominallystationary roll for limited movement toward and from the operativeposition of the movable roll; means mounting the movable roll for bodilyswinging movement to and from its operative position; fluid pressureresponsive means for pressing the nominally stationary roll onto. theother roll; fluid pressure responsive means for biasing. the normallystationary roll away from the other roll; fluid pressure, responsivevmechanism for swinging the movable roll to. and from its operativeposition; and a single variable volume constant pressure pump forsupplying fluid under pressure to all of said fluid pressure responsivemeans.

3. The combination set forth in claim 2 further characterized by theprovision of: a manual control governing the application of fluidpressure to the fluid pressure responsive mechanism which swings themovable roll to and from its operative position; and automatic controlmeans actuated by a part moved by said mechanism as the movable rollassumes its operative position for governing the application of fluidpressure to the other fluid pressure responsive means.

4. In a machine, the combination of a pair of companion rolls betweenwhich work is gripped in the operation of the machine; means mountin oneof said rolls for limited movement toward and from the other roll whenthe latter is in its operative position; means mounting said other rollfor bodily swinging movement to and from its operative position; fluidpressure actuated mechanism for swinging said other roll to and from itsoperative position comprising, a fluid pressure motor, a rack movable bysaid fluid pressure motor, a pinion meshing with the rack, a rock shaftfixed to the pinion, a crank arm secured to said rock shaft, and linkageconnecting the crank arm with the mounting means for the movable roll,movement of the rack in one direction swinging the movable roll to itsoperative position and movement thereof in the opposite directionswinging the roll out of operative position; fluid pressure responsivemeans for pressing the first named roll toward its companion; a singlevariable volume constant pressure pump supplying fluid under pressure tothe fluid pressure motor and the fluid pressure responsive means; amanually operable valve controlling the application of fluid pressure tothe fluid pressure motor; an automatic valve controlling the applicationof fluid pressure to said fluid pressure responsive means; and a valveactuator fixed to a part of the motion transmitting linkage between thefluid pressure motor and the mounting means for said movable roll andpositioned to actuate the automatic valve to apply fluid pressure uponsaid fluid pressure responsive means as the movable roll assumes itsoperative position.

5. In a hide and leather working machine having a nominally stationaryupper roll and a movable lower roll swingingly mounted for movement toand from an operative position directly under the upper roll, thecombination with said rolls of: means for swinging the lower roll to andfrom its operative position; fluid pressure responsive means forpressing the upper roll down onto the lower roll; and means forautomatically connecting said fluid pressure responsive means with asource of fluid pressure as the lower roll assumes its operativeposition under the upper roll and for automatically disconnecting thesame from said source as the lower roll moves out of its operativeposition.

6. In a hide and leather Working machine, the combination of: an upperroll; bearings for the upper roll constrained to limited up and downmovement; a lower roll; pivoted arms mounting the lower roll forswinging movement to and from an operative position disposed directlyunder the upper roll; means applying an upward force upon the bearingsof the upper roll as long as the lower roll is in any but its operativeposition; and means for automatically applying a downward force uponsaid bearings as the lower roll assumes its operative position.

'7. In 9. hide and leather working machine, the combination set forth inclaim 6 further characterized by the fact that said last named meanscomprises a cylinder mounted above each bearing, a piston connected witheach bearing and operating in the cylinder thereabove, and means forapplying fluid under pressure to the cylinders above the pistons.

8. In a hide and leather working machine, the combination set forth inclaim 6 further characterized by the fact that said last named meanscomprises: a cylinder mounted above each bearing, a piston connectedwith each bearing and operating in the cylinder thereabove, and meansfor supplying fluid under pressure to the cylinders above the pistons toforce the pistons downwardly and thereby press the upper roll againstthe lower roll; means for supplying fluid under pressure to thecylinders under the piston therein to lift the upper roll; amultiposition valve controlling the application of fluid under pressureto said cylinders; means automatically actuating said valve to aposition at which fluid under pressure is fed to the cylinders above thepistons to press the upper roll down as the lower roll assumes itsoperative position; and means automatically actuating said valve to aposition at which fluid under pressure is fed to the cylinders under thepistons to lift the upper roll as the lower roll is moved out of itsoperative position.

9. In a hide and leather working machine, the combination of a pair ofcompanion pressure rolls between which the work is squeezed in theoperation of the machine, one of said rolls being nominally stationaryand the other movable; a pair of swingingly mounted arms carrying themovable roll and operable to swing the same to and from a positioncoacting with the nominally stationary roll; a rock shaft parallel withthe axis about which the arms swing; a crank connected to the rock shaftopposite the free end of each of said arms; a link connecting each crankarm with one of said arms; the crank arms being of such length that inone dead center position thereof the movable roll is in its operativeposition adjacent to the nominally stationary roll to close the machine,while in the other dead center position thereof the movable roll isswung its maximum distance from the nominally stationary roll to openthe machine; a pinion fixed to the rock shaft; a rack meshing therewith;a fluid pressure motor connected to the rack for reciprocating the same;bearings in which the nominally stationary roll is journalled; fluidpressure responsive means connected with said bearings and by which saidbearings may be forced toward the operative position of the movableroll; means for supplying fluid under pressure to said fluid pressureresponsive means, including an automatic valve actuated by the motion ofthe rock shaft during its final range of movement in closing the machineso that said fluid pressure responsive means becomes operative as themachine closes; and manually operable means for supplying fluid underpressure to the fluid pressure motor so that the closing and opening ofthe machine is under manual control.

10. In a hide and leather working machine: companion upper and lowerpressure rolls between which work to be acted upon passes; meansmounting the upper roll for limited up and down movement; means mountingthe lower roll for bodily swinging movement to and from its operativeposition below the upper roll; fluid pressure responsive mechanism forswinging the lower roll to and from its operative position; fluidpressure responsive means for biasing the upper roll upward; fluidpressure responsive means for biasing the upper roll downward; manuallyoperable valve means controlling the application of fluid pressure tosaid fluid pressure responsive mechanism so that the swinging of themovable roll to and from its operative position is under manual control;valve means controlling the application of fluid pressure to the twofluid pressure responsive means which act upon the upper roll, said lastnamed valve means allowing fluid pressure to be applied to only one at atime of said two fluid pressure responsive means; and actuating meansinterconnected with the mechanism for swinging the lower roll to andfrom its operative position and operable to actuate said last namedvalve means to effect the application of fluid pressure upon said twofluid pressure responsive means so as to 9 apply a downward bias uponthe upper roll as the lower roll assumes its operative position and toapply an upward bias upon the upper roll as the lower roll is swung awayfrom its operative position.

RALPH J. STEHLING.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,940,825 Smith Dec. 26, 19332,054,443 Pierson Sept. 15, 1936 2,094,761 Stehling Oct. 5, 19372,317,493 Stout et a1 Apr. 2'7, 1943 2,334,588 Smith Nov. 16, 19432,399,819 Moore May 7, 1946 2,434,367 Mofiatt et a1. Jan. 13, 19482,471,984 Stehling May 31, 1949 FOREIGN PATENTS Number Country Date433,564 Great Britain Aug. 16, 1935

